Senior Mechanical Engineer

Senior Mechanical Engineer

Helix Earth (Houston, TX 77004) is a rapidly growing startup on a mission to combat climate change by transforming the way we cool our planet and is transforming the way we do carbon capture and sequestration (CCS). We're looking for exceptional talent to join our journey. Born from innovations originally designed for NASA's space exploration, our groundbreaking solutions are now being adapted to revolutionize air conditioning energy efficiency and in addition are being used to pioneer revolutionary CCS technologies. If you're eager to contribute to a greener future and be part of a team that's shaping the forefront of sustainable technology, then Helix Earth is the perfect place for you to make a difference. Join us in creating a cooler, cleaner planet for generations to come.

Helix Earth is seeking a Senior Mechanical Engineer, who will report directly to the Engineering Manager and Lead Engineer. The position will be onsite and located at our Houston, TX offices.

About You

• You are a hands-on mechanical engineer who brings rigor and creativity to subsystem development from concept through production.
• You know how to take designs through NPI, including drawing release, SOPs, and supplier readiness.
• You evaluate potential risks in design, processes, and components, and reduce them using FMEA, root-cause analysis, and validation tests.
• You thrive in fast-paced startup environments, designing, building, and iterating quickly to deliver robust, reliable hardware.
• You have a strong grasp of fundamentals (mechanics, materials, heat transfer, fluids) and use structured methods like design of experiments (DOE) to drive decisions.
• You are fluent in modern computer-aided design (CAD) tools (SolidWorks or equivalent) and comfortable taking designs into the shop to prototype and test.
• You collaborate naturally across electrical, controls, and manufacturing teams to integrate subsystems cleanly and on schedule.

Job Responsibilities

• Lead mechanical subsystem design from concept to pre-production, owning architecture, CAD, drawings, and specifications.
• Plan and run design of experiments (DOE) to validate performance, reliability, and safety; analyze results and drive design updates.
• Build and iterate prototypes (rapid prototyping, machining, additive) and develop test fixtures and methods to evaluate components and assemblies.
• Lead the design & validation test process, including test plans, instrumentation, data collection, and reporting for design reviews.
• Plan and execute subsystem and component validation, including test strategy, fixture development, acceptance criteria, and results reviews.
• Lead reliability testing at component, subsystem, and system levels, including test plans, stress screening, root-cause analysis, and corrective actions.
• Drive DFM (design for manufacturing) and readiness for pilot builds in collaboration with manufacturing partners and suppliers.
• Own NPI transition activities for assigned subsystems, including CAD and drawing release with revision control, SOPs and work instructions, component selection and sourcing handoff, and build readiness with Operations and Supply Chain.
• Perform analyses (tolerance stacks, stress, thermal, fluids estimates) to inform design decisions and ensure requirements compliance.
• Create clear documentation: CAD, bill of materials, drawings with GD&T, validation and reliability test plans, and work instructions.
• Conduct FMEA (failure mode and effects analysis) and risk reviews; implement mitigations and verify via test.
• Collaborate closely with electrical and controls engineers on sensors, actuators, and interfaces for integrated subsystem performance.
• Support vendor selection, quotes, and bring-up; troubleshoot issues during prototype and pilot builds.
• Mentor junior engineers and establish best practices for review, test, and release gates.
• Contribute to continuous improvement of hardware testing, data quality, and iteration speed to support program milestones.

Qualifications

• B.S. or higher in Mechanical Engineering or related field.
• 5+ years of experience developing mechanical subsystems in a startup or fast-paced hardware environment, from design through pre-production.
• Proficiency with CAD (SolidWorks or equivalent), drawing creation, and revision control.
• Demonstrated experience with DOE, prototyping, and structured validation testing.
• Proven experience planning and executing subsystem and component validation with clear test methods and acceptance criteria.
• Hands-on ownership of NPI transition including drawing release, SOPs, and component selection and sourcing with Operations and Supply Chain.
• Experience leading reliability testing and closing issues via root-cause and corrective actions.
• Strong hands-on skills (shop tools, assembly, instrumentation) and a bias for action.
• Experience leading the design & validation test process (test plans, fixtures, data analysis, reporting).
• Working knowledge of DFM, GD&T, tolerance analysis, and supplier collaboration for pilot builds.
• Clear communicator with the ability to drive cross-functional alignment and deliver on aggressive timelines.
• Nice to have: HVAC design & controls experience; strong electrical engineering fundamentals for mechatronic integration; familiarity with compliance/certification processes (e.g., UL, ASME, IEC).

We're looking for exceptional talent to join our journey. Join us in creating a cooler, cleaner planet for generations to come.

Benefits

• Competitive compensation package with equity options.
• Comprehensive health, dental, and vision insurance.
• Paid time off, holidays, and flexible work schedule.
• Opportunity to shape cutting-edge sustainable technology with real-world impact.
• Collaborative, mission-driven culture with direct exposure to leadership.
• Career growth potential in a rapidly scaling startup.